We are a day closer now to the events leading up to what looks like another potent ocean storm for next week. All of the major global computer models show this happening to one degree or another. The run to run variability that we see in terms of strength and location is inevitable and it’s not time to focus on precise impacts for any one area. Instead, let’s look at what is likely to happen across a broad region of the U.S. coastline.

One key element of this storm, like the most recent Nor’easter, is that it is likely to remain offshore the entire time (at least as far as the U.S. is concerned). While it is possible that high latitude blocking via a large area of high pressure sliding in could send the storm back to the coast, it is not very likely. However, it does appear that quite a strong high will move in across the northern U.S. and across the Canadian Maritimes and this will combine with the low pressure of the ocean storm to create quite a strong pressure gradient.

It is this pressure gradient, the difference in the high and low pressure over distance, that I am most concerned about. The wind will not be particularly strong, nothing anywhere near what we saw with Sandy, but it will be around for several days, blowing across the Atlantic with increasing intensity. This will build the seas, creating large waves off shore. All of this energy will then be translated towards the vulnerable coastline from North Carolina’s Outer Banks to New England. You can clearly see this potential outlined in the graphic that I have posted in this blog. At first the wind will be easterly and directly onshore. Then, as the low tracks north, the wind will shift gradually to more northeast but the fetch will be significant. There will likely be several high tide cycles that will coincide with this event but fortunately, the Moon will not be much of a factor as it will be several days away from being full.

As far as inland snow or rain impact, it’s too soon to tell right now how much cold air will be in place but so far, the distance from the coast leads me to believe that the snow threat is going to be limited to the coast if at all. I do not see any indication right now that this storm will be a big snow maker for any one location. We’ll see as the picture gets clearer in the coming days but I am far more concerned about the coastal impacts of the increase in wind and wave action.

I’ll cover this topic at least once per day as I know many people in the region are concerned, rightfully so, about any coastal storm event that may hamper recovery efforts.

You can’t see it yet but a new coastal storm, a typical Nor’easter, is going to form off the Carolina coast tomorrow and track roughly parallel to the Eastern Seaboard and bring with it an increase in wind, rain, inland snows and a coastal storm surge.

All of the regional NWS offices are talking about the storm in their forecast discussions and it looks as though the areas hit hardest by Sandy will again be lashed by this system.

So far, the rain fall looks to be minimal enough to preclude any concerns about inland flooding. The heaviest rains will likely be near the coast which makes sense considering that this is a coastal storm and is not forecast to cross the coast or make a landfall. However, with many homes and businesses sustaining roof damage during Sandy, this rain is a serious issue and could cause further damage. If there is any chance to tarp open roof damage areas, now is the time to get it done.

Wind speeds will also be highest along the coast with gale force winds almost a certainty. From what I have seen, some of the strongest winds will be felt along the New Jersey and New York coasts with winds approaching 60 mph in gusts. This will be more than enough to knock the power back out for people who have recently had it restored. Here too, make sure any preparations to keep warm in case of power loss needs to be done now. Ask local relief agencies for battery powered lights and extra blankets today. The infrastructure is more vulnerable right now and it won’t take much to bring down additional trees and plunge large areas, especially near the coast, in to darkness once again.

Storm surge from extra-tropical storms such as this one can cause moderate tidal flooding which can extend in to back bays along the coast. Sadly, hurricane Sandy removed much of the protective dune system which will allow for more over wash and surge to reach in to some coastal towns. We could be looking at anywhere from two to four feet of flooding but a lot will depend on the track of the low and the duration of the long fetch of wind across the western Atlantic. A faster moving storm would be better, obviously. Again, from what I have gathered by reading the various NWS discussions, it looks as though the Wednesday night high tide will be the one of most concern – especially along northern New Jersey and some areas of Long Island.

As I have mentioned numerous times, utilize your local NWS info by going to weather.gov and inputting your ZIP Code. Read the content of the “Hazardous Weather Conditions” if the local office has put one up for the current storm. Here you will find more detailed information about timing and expected impacts to your local area. Keep in mind this is written by people in your region, not by a computer or from a cable TV news source. I highly encourage the use of the NWS local products, especially when it is important to understand the local impacts of a storm like the pending Nor’easter.

Luckily, the tropics are quiet with absolutely no areas to be concerned with in the coming days. We are nearing the end of a very busy hurricane season that will be remembered for generations to come because of Sandy and its legacy. For the people who are going through the painful and slow recovery process, hang in there. A lot of people are working to provide assistance for what is an overwhelming disaster. This current storm will be a set back for some, but it will not be nearly as intense or widespread as Sandy. That being said, it needs to be taken seriously and precautions taken to prevent further loss of life and even more damage to property.

I’ll post more here tomorrow morning with more specifics about what to expect as the storm begins to develop off the North Carolina coast.

I am very fortunate to have the opportunity to bring live weather data to the students and faculty of PS6, a wonderful school along the Upper East Side in New York City. Also known as the Lillie D. Blake School, they have worked hard to produce a roof top greenhouse project that will incorporate live weather data beginning this week.

Obviously, the weather controls almost every aspect of our lives, no matter how much we think about it. For the school, the weather will play a role in how their rooftop greenhouse and related projects fare over the coming years. By providing access to reliable and up to the second data, the students and the teachers will all be able to keep tabs on changing conditions, fair weather, rough weather and everything in between. In addition, there will be a live web cam installed so that they can monitor what the effects of the weather are.

The data will be hosted on this site at a link that I’ll post when it is operational later this week. In this way, anyone with Internet access will be able to get a look at the current weather conditions along Madison Ave in the Big Apple.

Note: I’ll be streaming the trip up and back live for our Client Services members, so log in, especially if you have not done so since last hurricane season, and say hello on the chat. This will be a nice practice run as we gear up for the 2012 hurricane season.

It appears that quite a potent storm is going to take shape over the eastern Gulf of Mexico this weekend as upper level energy digs in from the Great Plains. A surface low is forecast to form over the eastern Gulf and bring the potential for very heavy rain and severe weather to portions of Florida (figure 1).

Figure 1: Coastal Storm - 48 Hour Forecast from GFS

From there, the low is forecast to move up the East Coast, bringing with it wind and rain all the way to New England. For coastal areas, this will be basically a warm (relatively speaking) Nor’easter. If this were January, we would probably be looking at an epic snowstorm for a good deal of the East Coast. As it stand now, a decent rain event looks to be in store for a wide swath of the Florida peninsula all the way up to Maine with coastal areas experiencing rough seas and a stiff onshore flow (figure 2).

The storm is non-tropical in nature but will tap warm Gulf of Mexico water that is itself running well above normal for this time of year. This warm water will add energy and moisture to the storm system and provide the fuel for it to strengthen and dump copious amounts of rain along its track. If you have outdoor plans this weekend in Florida all the way to New England, keep up to date on the latest weather forecast for your area.

Figure 2: Coastal Storm - 60 Hour Forecast from GFS

One excellent tool to understand the impacts better of any storm event is to read the local forecast discussion from your National Weather Service office. You can find this by going to www.weather.gov and typing in your ZIP Code. Then scroll down on the landing page to find “Forecast Discussion”. It will have detailed meteorological information with timing, impacts and projected watch/warning info for any storm event forecast for your area. It’s a great tool, use it.

As forecast by the Storm Prediction Center yesterday, a significant, classic April tornado outbreak is underway across Kansas, Oklahoma and Nebraska.

Low-level winds are streaming in moisture from the Gulf of Mexico at tropical storm force in front of a deepening upper impulse coming out of the Rocky Mountains. Very cold air aloft and strong relative wind shear is creating an environment conducive for extremely strong, long-lived and violent tornadoes.

Significant severe weather is already ongoing in western Kansas, with a high-precipitation complex of storms entering central Nebraska.

As we progress into the evening, conditions will become even more supportive of strong/violent storms, especially into south/central Kansas and northern Oklahoma. The dryline will continue to move eastward…where the atmosphere is heating up and becoming more and more unstable. Baseball sized hail has already been reported with some of these storms…and the upper winds are expected to strengthen over the high-risk area during the next several hours.

NWS Wichita reports four storms are already occurring in western Kansas, all producing long track, violent tornadoes as of 4:10 PM Central time.

Residents in these areas, especially in central Kansas and northern Oklahoma should be prepared to move underground, if necessary, at any time this evening. Interior structures should be a shelter of last resort. Please get below ground in a basement or shelter if a tornado threatens your area tonight, and monitor local news and your NOAA weather radio for the latest information. Many of these storms will be strongest as nighttime approaches, so please monitor conditions very carefully tonight and stay close to shelter.